The present invention relates to a surface treatment equipment for treating circuit boards, and more particularly to such a circuit board surface treatment equipment which uses pressure-balanced water knives to eject a surface treatment solution onto circuit boards being carried through the equipment, enabling the surface of each circuit board to be well treated.
In a regular horizontal PTH type circuit board surface treatment equipment, water knives are operated to eject a surface treatment solution onto the surface of the circuit boards being carried through the equipment, enabling the surface of each circuit board to be treated. A water knife for this purpose is, as shown in FIG. 1, comprised of an elongated tube 1 having a longitudinal series of jet nozzles 11 through which the surface treatment solution is forced out of the elongated tube 1 to treat the surface of the circuit boards. Because the jet nozzles 11 have an equal diameter and are longitudinally arranged in a line, and the surface treatment solution is forced to the jet nozzles 11 one after another, the jets of surface treatment solution from the jet nozzles 11 have different pressure. Because jets of surface treatment solution are ejected onto the circuit boards at different pressure, the surface of each circuit board cannot be uniformly treated.